Car puller



May 5, 1953 F. H. HOGE ETAL CAR FULLER 8 Sheets-Sheet 1 Filed Jan. 30,1950 n mf H M. m m A m h m e e W Filed Jan. 30, 1950 8 Sheets-Sheet 2May 5, 1953 F; H. HOGE EI'AL 2,637,526

CAR FULLER InvenTro: Q FrederickH-Wgge 8 0 hi; rlgnd May 5, 1953 F. H.HQGE ETAL 2,637,525

CAR FULLER Filed Jan. 30, 1950 8 Sheets-Sheet 5 q L 1 w a H w E w 1% ism 3 Q s 1 "U h mm May 5, 1953 F. H. HQGE ETAL CAR FULLER Filed Jan. 550,1950 '8 Sheets-Sheet 4 Invenfors:

Frederick H-H eZr May 5, 1953 F. H. HOGE ETAL CAR FULLER Filed Jan. 30,1950 8 She'ets-Sheet 5 InVehToP- r Frederick H-H Jose hAM rap (W,

May 5, 1953 F. H. HOGE arm. 2,637,525-

- cm FULLER Filed Jan. 30, 1950 s Sheets-Sheet s Invenrom:

Frederick H.H0 e3r May 5, 1953 F. H. HQGE EIAL CAR PULLER Filed Jan. 30,1950 8 Sheets-Sheet 7 InvenTor-a:

Fred zrick H. Ho

8 Sheets-Sheet 8 F. H. HOGE E'I'AL CAR FULLER May 5, 1953 Filed Jan. 50,1950 Patented May 5, 1953 UNITED STATES PATENT ()FFICE CAR PULlLERApplication January 30, 1950, Serial No. 141,312

3 Claims.

The present invention relates to improvements in car pullers, and thelike. It will presently appear that machines embodying the features ofthe present invention may also be used for various purposes other thancar pulling; but generally the present improvements have been devised tomeet the special conditions of operation imposed in car pullingoperations. Specifically, also, the present features relate to two waycar pullers, that is, car pullers which are intended for pulling thecars in either direction as desired. The following statement of certainoperations will clarify certain of the operational functions for whichthe present machines are intended.

In various industrial operations it is necessary to advance a string ofcars with intermittent advancements during loading and unloadingoperations. Usually such advancements are made one car-length at a time,but other amounts of advancement may also be desired. For example, inthe loading of a string of tank cars it is fre quently necessary tobring each car in the string into loading position with respect to aliquid delivery pipe or spout so that the cars may be successivelyfilled with such liquid. This is true, for example, in tank car oilloading operations. Similar intermittent advancements of a string ofcars may be necessary during subsequent unloading operations. In eachcase, however, the

extent of advancement of the string of cars must be under such controlthat each car may in turn be brought to correct position with respect tothe loading or unloading: platform or wharf.

It is necessary to provide power means for moving the string of cars,and such power means must be under such control that it may be startedand stopped, and locked in stopped position in order to hold the stringstationary during the process of loading or unloading each car, and withsuch car retained in correct position for such ading or unloadingoperation. This means that the control of the string movements must besuch that the operator may start and stop the power unit at will andwith close accuracy so as to bring each car into correct position,regardless of the lengths of the various cars comprising the string, andregardless of the exact position along the length of each car at whichthe load is to be delivered to or removed from the car in question.

In order to hold the string of cars stationary in incorporates powermeans to move the string of cars in either direction as desired. by theoperator, means to normally look said power means against car pullingmovement until the operator moves the control element to position forcar pulling in selected direction, and control means to effect such carmovement in either direction with proper release of the brake meansduring the moving operation and re-setting of said brake means when thecontrol element is moved to position for discontinuance of car pullingmovement.

More specifically, it is a further object of the invention to provide acar puller unit which may be located at a convenient location withrespect to the track along which the car string is to be moved, togetherwith means to readily connect said car puller unit to the string of carsfor transmission of the necesary pulling forces. In this connection itis a further object to so arrange this connecting means that the samemay be readily attached to the car string for movement in eitherdirection as selected.

Specifically, the connecting means includes a loop of cable having oneside or pass of its loop extending parallel to the track along which thecar string is to be moved, together with simple means to connect onepoint of the cable to the car string so that cable movement will drawthe car string along the track. The ends of said cable loop areconnected to the car puller power drive in such manner that one end orthe other of the cable may be power pulled to thereby move the loop ofcable around its looping supports thus carrying said connection of thecable to the car string along the loop parallel to the track andcorrespondingly moving the car string as desired.

Still more specifically, the car puller unit includes two cable drums towhich the ends of the cable are connected, together with power drivemeans, and means to selectively connect said power drive means to eitherdrum for drive of such drum, with corresponding pull exerted on thecorresponding end. of the cable loop, for cable movement in the properdirection. In this connection, it is a further object to so arrange thecar puller elements that the power drive means rotates in the samedirection when driving either drum, thereby enabling the power drivemeans to be of the uni-directional type. When either drum is beingdriven the other drum is free from connection to the power drive means,and the winding of cable on the driven drum draws cable around the loopwith corresponding unwinding of cable from the non-powerdrlven drum,which non-power driven drum is rotated reversely during the winding ofcable on the power-driven drum.

The cable loop is defined by suitably located pulleys over which thecable passes. In order to avoid fouling of the cable passing over thesepulleys, and also to ensure good running of the cable in eitherdirection it is desirable to maintain the cable reasonably taut at alltimes and for movement in either direction around the cable loop. Sincedrive from the power-drive means is necessarily only to a single drum ata time, the non-driven drum turning free in the opposite direction forrelease of cable drawn onto the cable loop, it follows that in theabsence of restraining means for said non-power-driven drum said drummay rotate unrestrainedly with release of cable at too fast a rate sothat the cable of that portion of the loop between the power-driven drumand the point of car string attachment will be taut due to the pullingeffect of the power-driven drum, but the cabe length between the pointof car string attachment and the non-driven drum may become too loosewith possible fouling of such portion of the cable, and otherobjectionable results.

It is therefore a further object of the present invention to providedrum drag or brake means for each drum of the car puller which drag orbrake means will effect a sufficient dragging effeet on such drum duringunwinding rotation of such drum to maintain the cable sufliciently tautto ensure good running of the apparatus. It is a further object of theinvention to so form such drag or brake means that it will bepractically ineffective to exert any dragging or braking effect duringthe winding rotation of such drum. It is a further object of theinvention to so construct such drag means for each drum that thedragging or non-dragging effect of such drag means will occurautomaticaly and without the need of provision of special connections tothe other elements of the car puller or to the control means whereby thecar puller is controlled. Such drag means for each drum is so arrangedthat it is substantially ineffective during drum rotation in the windingdirection, and is effective for dragging purposes during drum unwindingoperation. By so arranging the drag means that it is substantiallyineffective during drum winding operation it does not impose anymaterial increase on the torque which must be delivered to the drumduring winding rotation by power drive.

A further feature of the invention relates to the provision of a commonshaft on which both of the drums are journa'led, power-drive means,means to drive said shaft by use of said powerdrive means, and means toclutch said shaft to either drum as selected by the operator. Means areprovided for elfecting clutch connection to either drum selectively,according to the direction in which the cable is to be moved, and meansto disconnect the other, previously engaged clutch means from its drumduring the clutching operation of the first mentioned clutch means toits drum. We have provided positive clutching elements or faces in theseclutches to ensure positive drum drive in the selected direction. Thetorque forces to be transmitted are sometimes very large, as when movinga train of more than a few cars, and consequently the driving forces tobe exerted against such clutch faces are correspondingly large. We havefound that under these onerous conditions of opera tion there is astrong holding force developed between the engaged faces of the clutchsuch force being sustained even when the driving force exerted throughthe clutch is released. It is necessary to disengage the loaded clutchfaces from each other before bringing about clutch engagement of theother clutch with its drum.

It is also a further feature of the present invention that we haveprovided positive braking means to restrain the drum shaft againstrotary movement when said shaft is not being powerdriven. When one drumis being driven by said shaft, its clutch being correspondingly engagedfor such drive, said engaged clutch transmits sufficient torque to drivesaid drum, according to the resisting force required to move the cableloop and the string of cars attached thereto. When such drivingoperation is discontinued, the car string having been brought to aselected position, the above mentioned braking means is made effectiveto lock the shaft against rotation, the cTutching means to such drivendrum remaining in engagement. By this arrangement the braking effect ofsuch brake means serves to hold the cable loop against reverse movement,such as might be caused by a grade on which the car string is carried;but generally it will also be found that when said braking means is madeeffective the cable being drawn onto the drum will be under hightension, so that upon setting such brake means the clutch faces willremain under heavy force engagement.

Due to the large forces transmitted through the clutch faces, and bothof the conditions explained above, it has been found that in the absenceof special provision it is necessary to exert large forces in the axialdirection of the shaft in order to disengage the previously engagedclutch. We have therefore, as an important feature of our presentinvention, so formed the clutch faces that they may be readilydisengaged when the clutch is to be disengaged, and still said faceswill transmit the required forces from the shaft to the clutched drum.To this end we have formed the clutch engaging faces with a slight slantbackwardly from parallelism to the drum axis so that during thedisengaging movement of the movable clutch element (which movement is indirection parallel to the shaft axis) there is an immediate tendency forthe companion clutch faces to disengage from each other. This tendencyis proportionate to the sine of the backward angle which said clutchfaces make with respect to a plane extending through such clutch facesand parallel to the shaft and drum axis. The clutch faces of both clutchelements are formed on the same angle (just referred to), so that whenthe clutch is engaged the companion faces of the two clutch eiementscome into fiat engagement with each other for transmission of drivingforces.

Since the driving forces are transmitted through these faces which areformed at a slight angle with respect to the plane parallel to the r'shaft axis it follows that the driving force being transmitted betweensaid faces will create a component of force in the direction of theshaft axis. This force tends to cause the clutch elements to disengagefrom each other. By forming the faces at an angle less than the anglecorresponding to the coefficient of friction between the metals fromwhich the clutch elements are formed this disengaging component of forcewill not be large enough to cause clutch disengagement under staticconditions of force transmittal; but due to vibrationsand the likeattendant on the operation of the car puller there will actually becreated a tendency for the two clutch elements to disengage unlessrestrained from such disengagement. Accordingly we have made provisionfor locking the drums against endwise movement along the shaft in thedisengaging direction, and we have also provided for positively lockingthe movable clutch element against disengaging movement from thecorresponding drum clutch during driving engagement of the two clutchelements with each other. Accordingly when the movable clutch element-ofone clutch has been engaged with the corresponding drum clutch elementfor drive of such drum said movable clutch element is restrained againstdisengaging movement until the clutch elements are purposely reversedfor drive to the other drum.

We have provided motor means to shift the clutch elements for change ofdrum drive, and suitable connections from such clutch motor to theclutch moving elements. In this connection We have also provided brakemeans in connection with clutch shifting motor and connections, whichbrake means is normally engaged for braking when the motor is notenergized to shift the clutch elements. This braking means thereforeserves to strongly retain the clutch elements in that position to whichthey have been moved;

and also serves to receive and resist the tendency for the clutchelement to be moved away from engagement with the corresponding drumclutch element during drive.

The clutch shifting means includes means to shift both of the movableclutch elements (for the two drums) harmoniously in either direction asrequired for clutch change. Since the clutch each clutch looktowards'eac-h other it follows that when such clutch is to be engagedthese elements must come together in such manner as to allow theirdriving faces to come into registry without difficulty in case themovable clutch element and the corresponding drum clutch element do nothappen to occupy exactly the correct posiengaging portionsofthe-companion elements of tions to allow them to be immediately broughtinto final driving registry. Thus, in case the drum happens to occupy anangular position such that its clutch teeth will prevent complete clutchengagement provision must: he made to allow for subsequent completionof'the clutch face engagements. We have made such provision herein.

In connection with the foregoing we have also made provision forpositively withdrawing the previously engaged clutch element from itscorresponding drum clutch element, and for at the same time applying tothe previously nonengaged clutch element a yieldable force'suflicient tonormally move such clutch element in movement; and thereafter as theshaft is powerrotated the yieldably pressed clutch eement will move intocomplete enga-en1ent with the corresponding drum-clutch element, andthereafter power drive to the now completely clutched drum will occurand will continue as long as desired.

We have mentioned that the driving forces to be transmitted throughthese clutches may be very large. We have therefore provided a numher ofclutch engaging faces on each clutch unit, there being six such faces oneach element of each clutch in the construction hereinafter described.These faces should be very accurately finished so as to ensuretransmittal of drive to all of these faces with corresponding divisionof the total force between the several faces simultaneously engaged.There will, however, be wear of such faces with heavy usage of the carpuller and corresponding frequent shifting of the clutches from oneposition to the other. In order to enable removal and replacement ofworn or imperfect clutch elements without the need of completelydismantling thev drums from the shaft of. the car puller We havesectionalized each clutch element or ring'so that said sections may beindividually disconnected from their supporting bases, and so thatproper replacements may thereafter'be made and secured in place. Theseclutch sections are also so formed and supported that the large drivingforces delivered through them are transmitted through tongue and groovesupports which extend substantially radially or the units.

Even when the clutch faces are accurately finished so as to ensure gooddriving engagement between all or most of the faces of each clutch,still it is evident that dirt or other foreign matter gathering on saidfaces would destroy such intended result of plural face drive, withattendant increase of driving forces on. the faces doing the driving.Furthermore, it is intended, as previously stated, that; theactualengagement of the moving clutch element with thecompanion drumclutch element shall cccur'under such yieldable force condition, in casethe two clutch elements were not in exactly correct relative. positionswhen clutch shift occurred. To ensure this result it is desirable toavoid creationv of unintended frictional resistance to clutch movementas by accumulation of dirt and the like on the relatively movablesurfaces of the shaft and the movable clutch element.

We have therefore provided for enclosure of the clutch elements andtheir surfaces within substantially tight enclosures-which willeffectively prevent the incursion of dirt and other foreign matter tosaid parts. These enclosures are of such form and nature that theypermit of necessary rotary drum movements while the clutch shiftingelements do not correspondingly rotate; and also these enclosures are ofsuch form and nature as to permit of the necessary back and forth,movements of the clutch shifting elements which must extend from withinsuch enclosures to locations outside thereof so that they may beproperly actuated.

A further feature of the present invention conoerns itself with theprovision of remote control means to control the direction and startingand stopping of movements of the car puller unit so that said unit maybe controlled from points remote from the unit itself, and from pointswhich are convenient to the operator or person in position to observethe car which is being brought into loading or unloading position.Thereby it is possible to operate the car puller to ensure exact carpositioning at the loading or unloading stand.

, In connection with the foregoing we have also made provision forensuring stoppage: ofcar 7 puller operation at limit positionscorresponding to permissible limits of car puller or other movement.Conveniently these limit switches are 'functioned by engagement ofsuitable clamps carried by the draw cable itself so that these clampsmust move in exact harmony with the car pulling connection itself. Thedraw cable passes over suitable pulleys defining its path of travel, asalready stated, and there will necessarily be varying degrees of sag inthe cable between these supporting pulleys. Accordingly the "clampscarried by such cable will change in elevation during cable travel andtherefore provision must be made to ensure proper registry of suchclamps with the limit switch operating elements as the clamps approachsuch limit switches. We have made such provision in the presentdisclosures.

Other objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of constructionand combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a front elevation of a car puller unit embodying thefeatures of the present invention, the clutch shifter being moved toposi- .'55 of Figures 1, 2 and 3, looking in the directions of thearrows;

Figure 6 shows a cross-section taken on the lines 66 of Figures 1, 2 and3, looking in the directions of the arrows;

Figure 7 shows a fragmentary section taken on the lines l'! of Figures1, 2 and 3, looking in the directions of the arrows, but on enlargedscale, and this section shows the details of the drag element of theright hand drums;

Figure 8 shows a detailed elevational view of the bracket whichpivotally supports the lever bar of the drag shown in Figure 7;

Figure 9 shows a fragmentary section taken on the line 9-9 of Figure '7,looking in the direction of the arrows, but on enlarged scale;

Figure 10 shows a plan view of the reciprocable bar for shifting themovable clutch elements, on

enlarged scale as compared to Figures 1, 2, 3, 4,

and 6;

Figure 11 shows a side elevational view corresponding to Figure Figure12 shows a fragmentary horizontal section taken on the line I 2--l2 ofFigure 6, looking in the direction of the arrows; and it shows anenlarged detail section through the companion left hand clutch elementsin disengaged position;

and this section shows one form of guard around the clutch engagingelements which guard bears against the adjacent end face of thecorresponding drum with a rotary sliding engagement to allow for drumrotation while the guard remains stationary; and Figure 12 is also asection taken on the line [2-12 of Figure 13, looking in the directionof the arrows;

.in the one direction or the other.

. Figure 13 shows a fragmentary section taken on the line l3l 3 ofFigure 12, looking in the direction of the arrows, and this figure showsa detail face view of one of the companion clutch elements, showing thesectionalized form thereof;

Figure 14 shows a fragmentary section taken on the line l4-lll of Figure13, looking in the direction of the arrows, and it shows the fact thatthe engaging face of the clutch element is formed at an angle withrespect to the plane passing through such face and through the axis ofrotation;

Figure 15 shows a fragmentary section taken on the line I5-I5 of Figure13, looking in the direction of the arrows, and it shows the tongue andgroove connection of the clutch section element with the base by whichit is supported;

Figure 16 shows schematically a typical layout of an application of thecar puller improvements herein disclosed to a two track loading orunloading and/or filling location, the central portion of the layoutbeing cut away to shorten the figure;

Figure 17 shows a schematic wiring diagram for the circuits of thelayout shown in Figure 16;

Figure 18 shows a plan view of a form of limit switch operating unit;

Figure 19 shows a side elevation of the unit shown in Figure 18;

Figure 20 shows a layout for movement and control of a car string by useof a car puller embodying the features of the present invention, similarto the layout shown in Figure 16; being a layout in Which the car pulleris located between two adjacent parallel tracks with the two 'sides ofthe cable loop extending parallel to said tracks, and with fixtures forconnecting cars on either or both of said tracks to the cable for carmovement on either or both of said tracks;

Figure 21 shows a layout for movement and control of a car string by useof a car puller embodying the features of the present invention, whereinone run of the cable loop lies parallel to a track, and the leads to andfrom the car puller drums extend at right angles to the direction of thetrack, with the car puller located adjacent to one end of the tracksection along which cars are to be moved, or adjacent to one end of therun of cable attachment;

Figure 22 shows a layout similar to that of Figure 21, but with the carpuller located between the two extreme limits of movement of theattaching fixture by which the car string is at positions of limitedmovement of the bar H0 Figure 23 shows a fragmentary front elevationalview of a modified form of shifting means for the clutch operating bar,being a manually operated arrangement; and

Figure 24 shows a plan view corresponding to Figure 23.

Referring first to Figure 16, the car puller unit is designated in itsentirety by the numeral 30. It includes the two drums SI and 32 whichare freely journalled to the shaft 33, and clutch elements 34 and 35 areprovided whereby either drum may be selectively clutched to said shaftby shifting the clutch bar I l0 towards one drum or the other. Theclutch control motor 37 is provided for effecting movement of thi bar H0in one direction or the other, such motor being reversible andcontrollable from a distance if desired. The two limit switches 38 and39 are provided for cutting off this clutch control motor at positionsof limited movement of the bar H0 This clutch motor assembly is providedwith a normally set brake element 40 so that when said motor is notenergized said brake is locked to hold the motor, and also the clutchbar H against movement until the clutch motor is again energized formovement to shift the clutch bar in the other direction, to the oppositeclutching position.

The shaft 33 may be driven by a power motor 4i through a gear reducerelement t2, and the power motor shaft 43 .is provided with a brake wheelor pulley 44 which is normally engaged by suitable brake shoes tonormally lock said wheel against rotary movement, thus normally lockingthe shaft 33 against movement when the powermotor is not energized. Thusthe drum it for .32 which is at the time clutched to said shaft willalso be locked against backward rotation, that is, rotation against thedriving direction of such clutch. Each drum is provided with a dragwhich will exert an adj Listed amount or braking action against backwardrotation of such drum, that is, a braking action to resist unwindingrotation of such drum; but drag is so arranged that it is substantiallyineffective to exert any substantial amount oi braking effect when r thedrum is being rotated in the forward or winding direction. These dragsare shown at 4'5 and A6 in Figure 1b.

The layout shown in Figure '16 is one in which the car puller is adaptedto move ears on either or both of two parallel track sections. These arethe tracks '4? and 18. A pulling cable 49 extends from an anchor to onedrum, along the track section t"! and parallelthereto for a distancecorresponding to the specified amount of car pulling movement, to thepulley 50. From this pulley 50 the cable is carried over to a pulley ia'cliacent to the extreme limit of car pulling movement for the track48, and thence the cable extends along parallel to the track section t?)to the drum 32 to which drum the other end of the cable is anchored. Thedrums are or such size as to allow for winding a length or cablesomewhat longer than the maximum specified amount or car pullingmovement. The cable is pro vicled with a ring or other suitable fixture*52 at a proper position in its length, and the car string is connectedto this ring or fixture by means or a short length of cable 53 which hasthe hook or other suitable fixture 5 8 secured to itsend. Reference toFigure 20, which is a showing of a layout similar to that of Figure 16,will show that this attaching hook or fixture 54 should be capable ofeifective movement through a distance sutllcient to meet the requirementsfor cable pulling along the track section "it. A similar attaching hookand the corresponding ring 5 and 5b are provided in that portion 'of thecable lying parallel to the track section '41, and these must be capableof movement 'along that track section for a distance sufiicient to "meetthe requirements of that track section. In this layout one attachingfixture is adjacent to the car puller unit location, it, when the other'alfta-ching fix- "ture is at the far end of the track section, and

as one fixture moves towards the car puller unit the other fixture movesaway from the tear puller "mi'it, vice versa. In other words, the carattaching fixtures are carried by the cable loop,

and each such fixture must be capable of making the necessary extent ofmovement parallel to the track section being served by it.

When the fixture 5'5 is closest to the drum 3'! there is wound on saiddrum an amount of cable su'ffici'ent to allow for -movement of saidfixture away from the drum a distance at least equal to the full travelof said fixture away from the drum; and the movement of said fixture 55away from the drum 34 is effected by winding of cable on the other drum32, such winding drawing cable over the two pulleys 53 and 51. Also,during such winding of cable onto the drum 32 the fixture 52 isapproaching the drum 32 and the cable is winding onto said drum; andsaid drum must be capable of receiving a length of cable suiiicient toaccommodate the amount of move-- ment of the fixture 52 along the tracksection 48. By attaching both of the cable end portions to theirrespective drums in such manner that the lays of cable running from:both of the drums are either from the bottom or the top tangents of thedrums it is .seen that for cable movement in either direction the twodrums will rotate oppositely. Thus, by bringing both runs of the cableoff from the bottom tangents :of their drums, winding rotation of onedrum will be clockwise when viewed from the lower edge of Figure 16, andthe unwinding rotation of the other drum will be counterclockwise whenviewing the car puller unit from the lower edge of Figure 16. The shaft33 is always driven the same direction for drum drive, being clockwisewhen viewed from the bottom of Figure 16., and when one drum is clutchedto said shaft the other drum is unclutched from said shaft but isrestrained .from too free rotation counterclockwise by its drag brake.The details of construction of the unit 3% will be described presently.

In the layout shown Figure .21 the single track section 32 is served,the cable length 58 of the cable loop extending parallel to this tracksection, and the fixture 59 being connected into this cable lengthinlayout the cable passes over the two ulleys Bil and 64., defining thecable length 58, and the cable returns from the pulley Bil, passing overthe additional pulley 62.. From the pulleys iii and 62 the cable extendsto the two drums 32 and 312., respectively. this layout the car pullerunit is located adjacent to one extreme limit of car pulling movement.In Figure 22 there is shown another form of lay-out similar in somerespects to that of Figure 21.; but in the present case the carzpuiliter unit is located at a position between the two limits or carpulling movement, and to do this the cable is also brought over theadditional pulley 53. It will be observed that in the arrangement ofFigure 20 the shaft of the car puller unit extends at right angles tothe direction of car pulling movement, whereas in both of Figures 21 and22 the shaft of the car puller uni t extends substantially parallel tothe direction of car pulling movement. Also, in Figure '21 the "carpulling unit .is located adjacent to one extreme of car pullingmovement, whereas in Figure 22 the car pulling unit is located withinthe limits of car pulling movement.

The several layouts thus described are typical of some applications ofuse of the car puller unit herein disclosed, and are not to beunderstood as illustrating all of the possible applications of use ofsuch oar puller unit .as various :other applications of such use willsuggest themselves to the engineer.

Provision has been made .ior control of the .car puller unit for pullingin either direction, and for stop-ping at any exactly selected position,and for locking the car puller .at stopped position; and such controlsmay be eflected either locally at the location of the car :pnlle-r unit,or remotely, from one or more remote control stat-ions, as will 11 behereinafter disclosed. Such remote control stations, when provided, maybe located at points convenient to the person supervising the caroperations, and/or at points where the cars may be readily observed asthey are successively brought into loading or unloading positions.

The car puller unit includes a suitable base section 64 which isprovided with a long front portion which carries the pedestals for theshaft journals, etc., and said base section is also provided with arearwardly extending back portion which carries suitable pedestals forcarrying the power motor, the brake therefor, and the rear portion ofthe gear reducer.

The shaft 33 is Journalled at its ends in the bearings 64 and 65 carriedby the pedestals 66 and 61 which extend up from the base section.Journalled on this shaft symmetrically with respect to the center lineof the unit, are the two drums 3| and 32, already referred to. Each ofthese drums is provided with the end flanges 68 and G9 to limit cablelaying, and preferably each drum surface is smooth and un-grooved. Thecable carrying capacity of each drum is sufiicient to accommodate alength of cable somewhat greater than the maximum cable movement forwhich provision has been made, and corresponding to the maximum carpulling movement intended. Such amount of cable may be received on thedrum in one or several lays according to the design of the car pullingunit. When more than one lay of cable is made the incoming cable willexecute its lays progressively without the need of providing a specialcable layer, as will hereinafter appear. The cable ends are anchored orsecured to the respective drums close to the flanges thereof, and whenthe attaching fixture 52 is at one extreme of its movement there iswound on one drum an amount of cable somewhat more than the total carpulling movement, and there is wound on the other drum some small amountof cable to take care of emergencies and avoid unintended locking ofmovement due to lack of spare cable on the drum. Furthermore, both cableends are brought to their respective drums preferably at the bottomtangents to said drums, as already explained. Accordingly, for clockwisedrum rotation when viewing the unit as in Figure 6 (also when viewingthe unit from the bottom of Figure 16) cable will be drawn onto thedrum; and release of cable from a drum must be accompanied bycounterclockwise drum rotation.

The power motor 4| is a uni-directional motor. It drives the high speedshaft 70 of the gear reducer element 42 through the coupling H, and thepower brake element 44 includes the brake drum 12 which is normallyengaged by the brake shoes 13 under effect of the brake setting spring14 so that this brake is normally set or locked. There is provided asolenoid '15 which when energized will draw its armature 16 down todisen age the brake shoes against the force of the spring 14, thisarmature acting through the lever arrangement 11. Thus the brake may bedisengaged by supply of current to the solenoid T5, and suchdisengagement will continue only as long as said solenoid is energized.The arrangement is such that this solenoid is energized concurrentlywith supply of power current to the motor 41, and so that as soon assaid motor is de-energized the brake will be set by its spring i 4 tolock the shafts against rotation.

The gear reducer may be of any suitable design, and the details ofconstruction thereof need is one having the reducing gear trainincluding the pinion 18 meshing with the gear 79, the pinion 80 meshingwith the gear BI, and the pinion 82 meshing with the final or low speedgear 83. This final gear is keyed to the shaft 33 to drive the same witha very large possible torque. The arrangement illustrated is one havingan overall gear ratio of substantially 233/1, so that the final shaftspeed will be l/233 of the speed of the motor 4|, and the deliveredtorque will be 233/1 of the motor torque (disregarding usual losses).Since the shaft 33 need be driven in but one direction the power motorand its controls may be for uni-directional motor operation. In theshowing of Figure 5 the motor shaft 70 should rotate clockwise whenviewed as in Figure 5 in order that the shaft 33 shall rotatecounterclockwise when viewed as in that figure, corresponding toclockwise drum rotation when viewed as in Figures 6 and 16.

Both of the drums are identical, both as to size and design, but theyare set onto the shaft 33 reversely, as is evident from various of thefigures, including Figure 3. These drums are provided with the recessedportions 84 facing towards each other. The inner hub end 85 of each drumis faced to receive a driven clutch element of ring form, 86, andslidably mounted on the shaft 33 are the companion ring form clutchelements 81. These clutch elements 8'! are carried by the correspondingmovable clutch carrier blocks 88 and 89 which blocks 88 and 89 are keyedto the shaft 33, by spline keys which allow for the necessary clutchingand unclutching movements to be executed.

Each driven clutch element 86 is provided with a number of teeth 90having faces 9| against which companion driving faces of the drivingclutch element 81 may engage. Likewise each driving clutch element 81 isprovided with teeth 52 corresponding to the driven teeth 90, and thesedriving teeth are provided with faces 93 which may drivingly engage thefaces 9| of the driven teeth 90. In Figure 12 the clutch element 81 hasbeen disengaged from the driven clutch element 86 by movement of thecarrier block 89 towards the right. Clutch engagement will occur bymovement of said carrier block towards the left in Figure 12, theposition of the drum and the driven clutch element 86 remainingunchanged along the shaft 33.

In the figures the clutch elements are provided with six teeth spaced at60 degree intervals around such elements. It is evident that these teethshould be accurately formed and finished in order that engagement of allor several teeth shall be ensured each time a clutch is brought intoclutching position. We have formed each of the clutch elements 86 and 81of sectional form, with one section corresponding to each tooth, as wellshown in Figure 13. These are the sections 81, 81 87, 81 87 and 81 shownin Figure 13, and the showing of this figure is also typical of theother clutch elements. These sections are shown as being held to thebases to which they are connected, by the screws 94, and these sectionsare also drivingly secured to their base supports by the key and slotarrangements as shown at 95 in Figure 13, and in Figure 15 in section.

With the foregoing sectionalized clutch element construction it isevident that said clutch elements may be removed and replaced or otherelements substituted from time to time if desired,

13' in ca'se of wear or need of refinishing the surfaces 9| and 93, orfor other reasons, without the need of completely dismantling the shaftand drum assembly of the car puller.

During driving engagement of a drum with the shaft 33 said drum ofcourse rotates with the shaft, being driven thereby. The other drum,unclutched, at the same time rotates backwardly on the shaft atsubstantially double shaft speed. Accordingly, we have journalled bothdrums on the shaft 33, by provision of the bearing sleeves shown at 96in Figure 3. These bearings may, if desired be lubricated by suitablemeans, not shown in the figures.

The shaft 33 is provided with a shoulder 91 at position for engagementby a thrust ring 98 set against the inner or clutch end of each drum;and adjacent to the outer end of each drum is a groove provided in theshaft to receive a split ring 99 for preventing outward end thrustofsuch at the outer end of such drum, to retain the drum in properlocation on the shaft regardless of such end thrust. It is also notedthat uch end thrust due to clutch drive is only developed while theshaft is rotating and transmitting force to the drum, but at such timethe drum is rotating with the shaft so that no frictional movement willtake place between the split ring and the outer end of the drum whilesaid split ring is under thrust load.

Each of the carrier blocks 83 and 89 is keyed to the shaft 33 as alreadyexplained. These carrier blocks are shifted back and forth to controlclutching and unclutching operations as follows:

Each carrier block is grooved as shown at I (see Figures 3, 6 and 12),and a split collar IOI is placed around such carrier block, beingprovided with an inwardly extending tongue I02 which en-' gages thegroove I00. This collar is provided with the opposite studs or pins I03,preferably extending out horizontally from the collar. rock yoke I04 isprovided for each clutch unit, and has its central portion provided withan opening of size suflicient to receive the collar IIII. Thisconstruction is shown in Figure 6. The yoke I M is formed of thecompanion sections I05 and H36 which are secured together; and thesection I05 is provided with the downwardly extend ng arm In! which ispivotally connected to a bracket I08 carried by the base section. Saidsection I05 is also provided with the upwardly extending arm I09 whichis controlled by means to be presently disclosed, for rocking the yokeon its lower end pivot, and to thus shift the carrier block 89- back andforth. Here it is mentioned that this shifting means is such that bothof the upwardly extending arms I09 for the two yokes are always movedsimultaneously, or harmoniously, in the same direction, so thatclutching function of one clutch is accompanied by unclutching functionof the other clutch. Generally the. unclutching function of one clutchwill precede the final termination of the clutthing function of theother clutch, for reasons which will presently appear.

At an elevation to effect convenient connectio'ns to the'tw'o upwardlyextending arms the outer end portions of these two slots to close saidouter ends, leaving open slots inwardly of such blocks H5 and H6. Theupper end portions of the arms I09 for the two yokes extend intoorthrough these open slot portions as well shown in Figures 1, 3 and 6.Each of the blocks I55 and H6 is provided with a downwardly extendingiug III which lies to the outside of the upper end portion of the arm I89, and an adjustable stop screw H8 is provided in each" of these lugsto establish a stop which will engage the edge of the arm I89. Each ofthe blocks IE5 and H8 is provided with an upwardly extending lug II!which serves as an abutment lying to the outside of the upper end of thecorresponding arm Hi9, and a spring I is provided between each such lugH9 and the upper end of the corresponding yoke arm IE9. Such springtherefore tends at all times to retain the Hi9 against the stop pin orstud H3, but the open portion of the corresponding slot I I3 or H4 issufficiently long, measured inwardly along the bar III to allow said barto move a certain amount in either direction without the inner end ofthe slot coming into direct engagement with the inner edge of the armI09. That is, in case the yoke at the left hand side of- Figure 3, beingthe yoke for the drum 3i, should be locked temporarily against movementtowards the left, such leftward movement of the bar I I0 couldnevertheless occur, the stop pin H8 moving away from the arm I09, andthe spring I29 which is connected to that. arm Hi9 stretching to producea force on the yoke arm. This spring force will tend to move that yokearm towards the stop pin H8 as soon as the restraining force which hasbeen holding the yoke against movement is removed. When such restrainingforce is removed the spring will draw the yoke to its full movedposition, and. until its arm Edd comes into engagement with the stop pini it at that end of the bar H0.

It will be seen that the foregoing functions are such that movement ofthe bar i i-0 in either direction will produce a positive disengag ingmovement of one of the clutch carrier blocks 88 and 39, to positivelydisengage the previously engaged clutch, and at the same time themovement of the other clutch carrier block will be under spring tension,of suflicient magnitude to ensure movement of that carrier block in theclutching direction until said carrier blocks movement may be barred bysome positive obstruction. When that condition occurs the continuedmovement of the bar' H0 will continue to move the first mentionedcarrier as about fully clutched condition. Therefore, as

soon as the obstruction which arrested the carrier block movement isremoved such carrier block movement will resume and will continue tocompletion for final and full clutching effect.

The arresting action referred to above will be caused by prematurecontact of the teeth 92 of the clutch element with the teeth 90 of theclutch element 86. That is, as the carrier block 89 moves towards theclutch element 86 the extreme faces of the teeth 92 will come intocontact with the slanting portions of the backs of the teeth 90 and fullmovement of the carrier block 89 cannot occur until the angular positionof the shaft and the carrier block 89 is correct to allow fullengagement of the teeth 92 with the teeth 90. Therefore it will almostalways happen that as the carrier block 89 is moved over in theclutching direction such arrestment will occur prematurely and with thespring I under tension. Thereafter as rotation of the shaft and thecarrier block occurs the teeth 92 will move to carry their faces 93towards the tooth faces 9| until finally contact of said tooth facesoccurs and drive of the driven element begins. Until such drivingengagement occurs the carrier block will move slowly to its finallyfully clutched position under force of the spring I20.

Referring again to the disengagement of the previously engaged clutch,during the foregoing change of clutching conditions, it will be seenthat such disengagement requires shift of the faces 93 of the previouslyengaged clutch element from the faces 9| of such clutch element.

These faces have previously been in driving contact and high pressureshave been transmitted through them. If these faces lie in planesparallel to the shaft, and the clutch disengagement is produced bymovement of the carrier element 89 without angular displacement withrespect to the shaft during such movement, the disengagement of theclutch faces will have to occur by simple sliding movement, and withoutany accompanying component of motion of one face directly away from theother face. It has been found that such an arrangement frequentlyrequires the application of very large forces to start thedisengagement, since the high surface pressures to which the surfaceswere subjected during power drive cause a molecular interlock of the twofaces which can be broken only by application of large forces when saidforces are parallel to the faces themselves. The foregoing condition isaggravated in the present instance by the following additionalcondition:

When drive has been occuring to one drum with corresponding wrap ofcable on said drum, said cable has been under large tension and it hasbeen necessary to transmit the needed large force through the clutchfaces to effect such drive. As the driving operation ceases (due tocutting off current from the power motor 4|), the power brake 44 sets inorder to retain the drum against any backward rotation and thus to lockthe car string in its new position. This braking action therefore occurswhile the cable wrapping on the drum is still under tension and stretch,and therefore the clutch faces are still subjected to the large forceswhich they were exerting at the time of discontinuance of the operation.If the terrain on which the track lies includes an upgrade up which thecar string is drawn it is evident that such grade will act to continuethe strong facial engagement of the'clutch faces indefinitely, and untilthe time arrives to reverse the clutch by proper movement of the barIIO. When that time atrives it will be necessary to disengage the clutchfaces while a very large force is still being transmitted from the facesof one clutch element to the faces of the other clutch element.

In order to provide for ready and relatively easy disengagement of theclutch elements from each other we have formed the teeth faces 93 (ofthe element 8'!) and the teeth faces 9| (of the element 86) at a slightangle backwardly from a plane extending through said faces and lyingparallel to the shaft axis, as shown in Figure 14. That is, these faces,instead of lying in planes parallel to the shaft axis actually lie inplanes which are tilted with respect to the shaft axis as will beevident from comparison of Figures 13 and 14. In the said figures thistilt amounts to substantially 6 degrees as shown in Figure 14, but we donot intend to limit ourselves to this exact angle nor to any other exactangle, except as we may limit ourselves in the claims to follow. Studyof this angular arrangement will show that even avery slight movement ofthe teeth 92 (carried by the carrier block 89) and without angularmovement with respect to the shaft itself, will result in immediatecommencement of direct disengagement of the faces 93 of said teeth fromthe faces SI of the companion teeth 90. No sliding movement of saidfaces over each other will be required to effect such disengagement.Another way of stating the matter is the followmg:

Due to the tilted form of the teeth any slight movement of one surfacewith respect to the companion surface, such movement being axial andunaccompanied by any rotary movement, will at once result in aprogressive separation of the faces of one set of teeth from the facesof the other set of teeth; and for any specified amount of movement ofthe teeth parallel to the shaft (due to carrier block movement) theamount of such separation of the tooth faces from each other will bemeasured as the amount of axial displacement multiplied by the sine ofthe angle of tooth tilt.

It is also noted that this slight tilt of the engaging faces of theclutch teeth creates a slight component of force in an axial directionbetween the companion clutch elements, and that such component of forcetends to disengage the clutch elements from each other axially. However,this component of force axially is very small compared to the fricticnalengagement between the companion teeth themselves and therefore is nevereven approximately sufficient to cause actual disengagement of thecompanion clutch elements. However, this arrangement of the companionclutch faces greatly facilitates the disengagement of the clutchelements when such disengagement is desired. Such formation of theengaging clutch faces is referred to herein as being one in which theteeth faces 9| are formed at a slight angle backwardly from a planeextending through said faces and lying parallel to the shaft axis.

The outer portion of each drum is provided with an extension I2I whichis formed with a cylindrical outer surface, and a slightly depressedsurface I22 is provided in such cylindrical surface. We have provided alever I23 pivoted at the point I24 adjacent to the extension I2 I. Thislever is conveniently pivoted to a bracket I25 carried by the basesection. A brake band I 26 new extends from one end or arm of the leverover the surface i222 to the other arm of "the lever, thefirst end ofsaidbrakeband being connected to the lever by the pivotal connectionI21, and the second mentioned end of'the brakeband being connected tothe lever by "another 'pi'vot'al connection its. The two points of"connection, 52! and Hill are located at different distances from thepivotal point of the lever l'ESGIf ZIZa, so that the two lever arms,124-12! and film-428 are of different lengths. The pivotal connectionHill is such as to enable production of 'a slight spring tension of thebrake handover the surface $22. For this purpose ablock laispivota llyconnected to the lever at the ans lZt, and a stud ['38 is freely passedthrough this "block 129, the end of the brake band being connected tothe stud I30 at the point I31. The stud carries an adjustment nut ll-l2on its projecting end "portion, and a spring :33 is located between thisnut and the block E29. By adjustment of this spring the brake band maybe placed under ,a relatively light normal tension so'tha't it-normallyengages the surface 122 with sufficient frictional engagement tostartproper-"braking or dragging response as will now be explained. a

' During winding rotation of the drum't'o which this drag device isconnected rotation will be. counterclockwise when viewed'as in Figure'l,and

unwinding rc'tation will be clockwise. The weight 1 or the lever itselftends to rock said lever clockwise (when viewed as in Figure '7), and ifdesired saidlever may be weighted as shown by the small weight let insaid figure. With this arrangement it will be seen that during unwindingrotation (clockwise) the brake band tends to follow the drum rotation.This tendency causes the brake band to follow the drum rotation clock-Wise for a slight angular displacement, thus .pulling up the bandconnection T21 slightlyand corrcspondingly slightly rocking the leverwith [resulting lowering of the longer lever arm lg'4 l2"$.] Necessarilyany rock of the lever clockwise will result in much greater movement ofthelonger arm i2 1'l28 than of the shorter arm TEA- ml. Accordingly suchclockwise rock must result in drawing the right hand end of the brakeband downwardly faster than the left hand end of said brake band isreleased upwardly, and this must result in a tightening of the grip ofthe brake band on the drum surfacel'ZZ. The-presence of the springallows some further lever movement to occur, due to grip of the band onthe drum surface, with corresponding tightening of the spring lilil, andcorresponding increased grip on t e drum surface. Thus the grippingaction of the brake band on the drum surface will increase untilresistance of the spring I33 prevents further lever rock, and thusarrests further increase of the braking effect. This condition have ingbeen attained, the continued drum rotation clockwise (unwinding) willoccur with a Jsubstam tially constant but large braking resistance, the

amount of such braking resistance being deter mined largely by thesetting of the nut 1'32 and the characteristics of the spring 133. It isintended. that this resistance shall besuch as to maintain the cabletaut as released from the unwinding drum, so that fouling of thereleased cable shall not occur, and to allow such cable re,- lease tooccur only at the rate called for by the winding of cable on the other'druin.

Conversely, during winding rotation of the This action will tend tocause the right hand 'nd o'fthelever'to rise with corresponding loweringor the left hand end of said lever. Accordinglythe pivotal point willalso rise and the pivotal point 127 Will fall, and the rate of such risewill be much greatert'han the rate of such fall. The result will 'bethat the grip of the brake band on the drum surface will be releasedinstead of beinginc'reased as previously'explained in the caseofc'lockwise drum rotation. Thus when thedrum is rotating for windingoperation the dragging action is reduced practically to zero. Thus thedragon thepow'er motor is reduced practically to zero, except for thatneeded to draw the cable onto the drum for normal car pulling operation.Preferably the band I25 includes a flexible metal strip I35 carrying aseries of formed coinpo'sition brake blocks use to contact the drum.

surface, in accordance with good braking pramtice.

Reference to Figure 3 will show the flexible boots 1 3'1 and I38extending from the gear reducer housing to contact with the inner drum Mends. These 'boots maybe made of suitable'sulo- 'stantia lly air tightmaterial such as rubberized cloth or the like secured to the reducerhousing aroundthe shaft bearings. These boots extend past the upwardlyand downwardly extending the cable winding and unwinding operations.

Conveniently the drum ends of these boots are provided withmetal ringsits and hit which directly contact the drum ends in sulostaritiallitight fashion, and if desired spring means may be provided to maintainthe rings use and Hill in firm "engagement with said drum ends. Theinwardly facing end surfaces of the drums may be finished to providesmooth surfaces "against which the rings 39 and ltfl engage. Thus theboots will maintain tight engagement with "the drumfehds while permittinnecessary drum roi bfi The foregoing arrangement will ensure againstentry of dust "or other foreign matter to the clutch faces, and willalso protect the oiled surfaced: the shaft from accumulation of suchdust andfo'reign matter throughout the zone of move-- ment executed bythe "carrier blocks 63 and '39 during "clutching and iinclutch'ingoperations.

This protection against entry of: dust and other matter to the clutchfaces is desirable in order to ensure maintenance of good drivingengagement of all of these surfaces during clutch drive.

The non entrance of dust and other foreign matter to the oiled portionof the shaft in the zone of in'ove ment of the carrier blocks isdesirable in order to prevent accumulation of hard or sticky matterWhere it will interfere with proper movementfof the clutch carrierblocks for their normal L n'latlter. 76 "rubber or drum shown in Figure'7 the brake band wlllten'd 'Ijnl ieures l2 "and 13 we have shown amodified folfln of boot for protecting the clutch engaging surfacesagainst entry of dust or other foreign In this case we have shown thedisk of c 'othermat'erial Iti extending outwardly fromfthe carrier blockradial face, and secured to saidface by the clamping ring M2. Theperipheral portion of this disk of rubber or the like provided with aring-of contact metal 143 facing-the inner end or the drum, and securedtightly. to the periphery of the rubber disk by a companion ring I44drawn towards the ring I43 by suitable means such as a series of throughbolts or screws, not shown. With this arrangement the flexibility of thedisk MI is suificient to enable necessary back and forth movements ofthe carrier block 89 while maintaining engagement of the ring I43 withthe drum end surface. In case of need to maintain sufficient pressure ofthe ring I43 against the drum end surface, leaf springs or the like maybe provided extending outwardly from the carrier block to engagementwith the ring I44, to press the peripheral portion of the disk I4I, orthe ring I43, into firm engagement with the rotating drum surface.

It is to be noted that the drums 3| and 32 rotate at slow speed, such as7 R. P. M., so that the engagement of the boot periphery of either theform shown in Figure 3, or the form shown in Figures 12 and 13 with thedrum end surface does not present difiiculties due to high rate of drumrotation.

Reference has been made to the motor 31 for shifting the clutch controlbar I I back and forth. This motor is reversible. It drives the gearreducer element I45 through the medium of the belt drive I45. The barIIO carries the rack bar I41 which is engaged by the pinion I 48 carriedby the final drive shaft I49 of the gear reducer I45. By this means theback and forth movements of the clutch control bar III] are causedbyrotation of the motor in proper directions. The brake element 40 isnormally set to its braking position by spring means, not shown, so thatnormally both the motor 3! and the pinion I48 are locked againstmovement. Thus the clutch bar III! is also normally retained againstmovement from a position to which it has been moved. The brake element48 is interconnected with the motor circuit for the motor 31 so thatwhenever that motor is being supplied with operating current said brakeelement 40 is released to allow motor operation with attendant movementof the clutch bar IIB.

In Figures 23 and 24 we have shown a modified form of device forshifting the clutch bar Ill] back and forth. In this modifiedarrangement we have provided a hand operated lever I50 pivoted to thetop of the gear reducer element 42 at the point I so that said lever maybe rocked back and forth manually. This lever is connected to the lugI52 projecting backwardly from the clutch operating bar III] so thatrocking movements of the lever I50 are delivered to the clutch bar IIDas direct back and forth movements of said clutch bar. In this case theoperator will effect change of clutch position by swinging the leverfrom one position to the opposite position, thus moving the clutch barto the opposite position. The operator will then hold the lever in suchnew position until the clutch has become engaged, after slight rotationof the shaft 33 if necessary, whereupon the operator may release saidlever, leaving the clutches in their newly attained positions. Or, ifdesired, means may be provided for latching the lever in either of itstwo extreme positions. Thus, the spring leaf I50 may be provided asshown in Figure 24, the same being anchored to the frame of the machineat I 50", and the outer end I5!) of this spring leaf may be providedwith notches in its upperedge into which notches the lever I50 will fallat the extremes of movement of the lever to lock the lever in suchextreme positions until the spring leaf is intentionally moved to permitdisengageduced, and arrestment of such movements, re-

ment of the lever for a reverse rocking movement of the lever.

Conveniently also we have shown in Figures 23 and 24 the flexible bootsI53 and I54 protecting the sliding supports III and I I2 whereby the barIII! is carried so as to prevent entrance of dust and other foreignmatter to these supports.

Reference to Figure 20 shows the guide pulleys I55 and I56 over whichthe cable pass runs, which guide pulleys are located near the respectivedrums 3| and 32. As the cable winds onto or unwinds off from each drumit must lay back and forth along the drum length in order to ensure goodlaying on the drum. It has been found that by locating these guidepulleys I55 and I56 at distances of not less than substantially sixtimes the axial length of the drum winding surface it is possible toensure good laying of the cable on the drum without the need ofproviding special cable layers for this purpose. If the drum dimensionsare such that several layers of cable must be accommodated on each drumit will be found that such placing of these guide drums I55 and I56 willensure good laying of the cable on the successive layers wound on thedrums.

As previously stated provision may be made for control of the car pulleroperations either 10- cally at the position of that unit or remotelyfrom'one or more control stands. These stands may be locatedconveniently where desired so as to enable the operator to observe thecar movements and make it possible for him to bring each car in turn tocorrect position. In case more than one such control stand or station isprovided all such stands or stations may be so interconnected as toprevent conflict of signals from them to the car puller unit 30, and toensure proper control from each stand in turn as used. Many electricalsystems are known for producing such remote controls as are needed forproperly controlling the unit 30, and therefore we do not deem itnecessary to herein disclose any such system in great detail. However,we have disclosed some of the elements or units of one such system sincethey are directly related in their functions to the proper control ofthe unit 30.

In Figure 17 we have shown schematically two remote control standsdesignated as East Control Station and West Control Station,"respectively. Each of these is provided with suitable buttons or otherelements whereby the unit 30 may be brought into operation for car pullin either direction as desired; and whereby the car pulling operationmay be continued as long as desired by the operator; and whereby the carpulling operation may be brought to stop promptly by the operator. Eachof these stations is also provided with control means designatedproperly according to the control operation-to be produced. Thus, eachsuch station includes control means designated as East, West, and Stop,these designations corresponding to directions of car movement to beprospectively. The arrangement illustrated is such that the followingoperations may and will be produced:

Assuming that the car puller has been at rest, and that the clutchingmeans stands in position with the drive elements clutched to the righthand drum, 32, in Figure 1, being the position shown in that figure; andassuming the drive v.ofthe drum 32 (as shown in Figure 1) produces "Eat?" car m vement; then operator movement of; the control button oieither control. station for East will at once place in operation thenecessary switches and control units, to release he power motor brake44, and supply p wer current to the power motor at, thus starting Eastmovement, the clutch g elements remaining in the pos tions which th yhad previously occupied. s nce it wasnot necessary to change dir tionof; tab e movement. Having thu bro ght the car uller into ope ation forEast move ment, such movement will continue as lone as e operator rtains the control elem nt East in operating position. or until hepresses the Stop buttonv or element. Thereupon. such East movement willstop, and the power brake M will be allowed to lock the shaft ta, thusalso looking the drum shaft 33 in the position of its stoppage, and thusalso looking the drum32 which is then clutched to said shaft 33..Subsequent and repeated East movements may be executed in like mannerfrom time, to time, each movement, being under complete control of. theoperator tobring theoar string to a newand contro ed position, of stoppae.

such operations in the East. direction may be QQlfltillued until the.maximum amount of, movement in. the. East direction has been executed,whereupon there will come into play a. limit swit which will preventfurther East, movements, b. 5. Wi11,,1,1,0 prevent reverse or West moements to occur, We. shall, disclose the tie-,- a ls of suc a limit.switch, p esently herein.

At any tim w en th ca puller is at, rest the operator may bring aboutWest movement;

To do this, he need only operate the West control button or switch atone of the. control stations. Upon doing this the following sequence ofoperations will take place: the clutch motor bralge element 40; will bereleased and current supplied to the clutch motor 31, in such manner asto cause that motor to move the clutch control bar H0, towards the left(in Figurel andelsewhere) This will cause; disengagement-of the clutchfrom the drum 3;! and move ment of theclutching elements to position forclutching engagement of the drum 31', all accord,- ingto the principlesof operation previously" explained herein. At the same time the powermotor lorake l l will be releasedand power currentwill be supplied tothe power motor' 4!, to drive' the shaft 33; and suchdriveof the shaft33 will be in the same direction as for the previously executed Eastmovements. Theclu-tching of the shaft 33 to the drum 3| will then hecompleted, as previously explained herein, and drive to that drum willthen proceed-in normal manner; Such West drive will continue as long as.the: operator maintains the W'estcon.- trol button in operatingposition, and until he presses the Stop button to discontinue theoperation When he presses the Stop button the: supply ofcurrent to the:power motor M will cease, and the: power brake id-will locktheshaft 43;against movement; to thus lock thedrum {l t stationary as will bereadily understood. It should: also be mentioned that when-theclutchoperating motor hasamoved the bar I lfl: to its extreme limit of."movement the limit switch 38 will: cutzofi the. current fromsaid clutchmotor 31 and, set thebrakc cc, to lock the clutch o s 22' clutchoperating bar- IiIl towards the right for proper reversal of clutchpositions.

Further and repeated West" operations may be produced from time to timeby operation of the West control button to institute each such repeatedWest movement, followed by operation of the "Stop button for stoppage ofeach such "West movement, as will be readily apparent. West movementsmay continue until there comes into operation a limit switch which willprevent further West movements, but which switch does not prevent Eastmovements to be executed for return of the cable to various East"positions.

It will of course be understood that various back and forth movements,first East, then West and vice versa, may be executed within the limitsof movement allowed :by the limit switches previously referred to.

The following further descriptions of operational elements related tothe foregoingcar puller unit will facilitate understanding of said carpuller operations.

Referring to Figure 2 the clutch control limit switches 38 and 39" areprovided with the rock arms I59 and IE0; respectively for operation ofsaid switches. These rock arms normally stand straight out, that is,rearwardly; as shown by the arm I59 of the switch 38, and in thisposition the switch is in its closed position; On the contrary, byrocking the arm i 59 or IE0 laterally; as shown by the arm l60- of theswitch 39-, theswitch is placed in its open position. The clutchoperating bar Ho carries a pin or lug I51 which will come intoengagement with either-the arm I59 or I 60, according to the directionof movement of thebar H0, to thus rock'the corresponding arm I59 or Hillfor switch opening movement, to thus terminate the supply of current tothe clutch motor 31, andto set thebrake 48, according to principlesalready explained; At" the time that one switch is thus caused 'toterminate current supply to the clutch-motor; circuits are alsoestablished so that when a control button of one ofthe control stationsis moved to the East or the West position (being that positionoppositeto the clutchposition prev-iously'occupied); current will come tothecl'utch motor '37" to drive" said motor and thus to reverse theposition of the" clutch operating bar H0; such reversingmovement thencontinuing until terminatedbyoperation of: the other limit switch 38 or39, as the case maybe.

Springs are provided, for returning the arms [59 and Hill-to theirnormal or-straightback positions; suchas theposition'of the arm959-,when the bar I 18 moveeaway from its previous position. Details ofthe cable movement limit switches are shown in Figures 1 8 and1-9'towhich reference may now be had. Each of thesc units: includes aswitch element proper, I62, having a rocl: shaft orpl n- Ifit whoseuppor end carries an operating arm i fi l by which said-shaftor-pinniay-b-erocked in one direction to thcreby move the switchcontacts to position oppositetothc position which theypreviouslyoccupi'ed-i The i switch also ineludes spring-means tendingtorestore the" switch to its originalorr-non-operated position, thusalso restoring thcarm i 64 'to its nonwperated position. Adjacent; to.the switch: element proper there is providedfla;verticalstud or pin onwhich is jcurna-lled. the. rock 2.1111: I 68 which carries the. pin; orlug: 16:1? which: will:- enga e the rock arm Hill oflthe: switchunit-.propeuwhen said arm F56 is; rocked: againstzth'e.torcaofaspring F63 tomove. said arrm azwayi-fronraar stop. pin- I89 Normally this: arm; I:isythusr retained-1 by theispringr I 68 23", against the stop pin, andlikewise the switch arm I64 is allowed to be returned to its normalposition by the spring within the switch unit. Under these conditionsthe limit switch does not discontinue operation of the car puller unit30.

The arm IE6 has hinged to it a further extension arm H0, such hingebeing shown at Ill. This hinge includes a horizontal pivot so that thearm ll!) may swing up and down on said hinge, the arm I66 not swingingup and down but remaining in its substantially horizontal plane ofmovement; and the hinge ill is such that lateral or horizontal movementor swing of the arm H will cause corresponding horizontal swing of thearm A66 no matter how much the arm ll'f! may be tilted up or down,within the limits permissible by the construction of the parts. Thus itis seen that lateral swings of the arm ill will cause correspondingswings of the arm 68 while at the same time said arm Ill] may be rockedup or down within rather large limits of'such rocking movement.

The limit switches of the type now being described are located close tothe cable run or runs, but in locations where said switches will notinterfere with other elements of the arrangement. The outer end portionof the arm N0 of each limit switch is slotted as shown at T2 and thecable runs through such slot, the outer end of the slot being closed asshown in Figure 19 so as to prevent the cable from disengaging from thearm. At a proper point the cable carries a button or the like, clampedto the cable, and travelling with the cable back and forth during carpuller operations. Such a button, H3, is provided for each limit switch,or in some cases one such but ton may be caused to serve both limitswitches. As such button approaches the limit switch arm ["39 and comesinto contact with said arm, further cable movement will cause the arm toswing against the force of the spring :33 until finally the switch isactuated to change the circuits and discontinue power motor operationand setting of the brake 44 of the car puller unit 33. Under thesecircuit conditions no further drive of the cable in the direction inwhich it has been moving may be caused, but the operation of the limitswitch so changes the various circuits that car puller operation may beinstituted in the opposite direction, reversal of the clutch operatingmotor 3? being included in such new operations.

The up and down swing of the arm llB, permissible on the hinge ill,makes it possible for the limit switch arm HG to follow the cable upand. down swings, and maintain proper relationship to the cable, so thatwhen the button I73 comes to the position of the limit switch the armlid will be properly swung to ensure limit switch operation.

We claim:

1. In a car puller the combination of a main drive shaft, means tojournal the ends of said shaft, separate winding drums journalled on theshaft adjacent to the shaft journals and between said journals, theinner ends of said drums facing towards each other and being separatedfrom each other, a toothed clutch element secured to the inner end ofeach drum, the driving faces of the teeth of both of said clutchelements facing in the same direction of drive, two independent drivingclutch elements drivingly and slidably mounted on the shaft between thedrum clutch elements, one for each drum clutch element, driving teeth onthe shaft clutch elements adapted to drivingly engage the teeth of thedrum clutch elements respectively. means to drive the shaft at a pointbetween said shaft clutch elements, and common means to slidably shiftboth clutch ele-- ments harmoniously in either direction along the shaftto thereby engage the teeth of one shaft clutch element with the clutchteeth of the adjacent drum and to disengage the teeth of the other shaftclutch element from the clutch teeth of the other drum, said shaftclutch element slidable shifting means including a reciprocable clutchoperating bar between the driving clutch elements, means to move saidbar in either direction selectively, a clutch actuator for each of thedriving clutch elements, an operative connection between each clutchactuator and the corresponding driving clutch element, a lost motionconnection between the clutch operating bar and each clutch actuator,each lost motion connection being so constituted as to allow movement ofthe clutch operating bar with respect to its corresponding clutchactuator by an amount of movement sumcient to permit full movement ofthe clutch operating bar in clutch engaging direction and away from aclutch disengaging position of the clutch operating bar withoutcorresponding movement of such clutch actuator, positive engaging meansbetween the clutch operating bar and each clutch actuator positioned toensure positive engagement of the clutch operating bar and each clutchactuator during movement of the clutch operating bar in direction tomove such clutch actuator in clutch disengaging direction, and springmeans between the clutch operating bar and each clutch actuator, eachspring means acting to urge movement of the corresponding clutchactuator in direction to engage the corresponding driving clutch elementwith the companion drum clutch element.

2. In a car puller the combination of two winding drums, means tojournal said drums for rotation, a toothed clutch element secured to oneend of each drum, a length of cable comprising a cable loop, means toconnect one end of said cable loop length to each drum, said clutchelement teeth facing in directions for drive of each drum in directionto wind cable on said drum with corresponding unwinding of cable fromthe other drum, an axially shiftable driving clutch element for eachdrum and having clutch teeth adapted to drivingly engage the teeth ofthe corresponding drum clutch element, means to drive both of theaxially shiftable driving clutch elements, and means to move both ofsaid axially shiftable clutch elements harmoniously to disengage one ofsaid clutch elements from driving engagement with the corresponding drumclutch element and to engage the other of said axially shiftable clutchelements with its corresponding drum clutch element, the engaging facesof the teeth of all of said clutch elements being formed as planarengaging surfaces slanting backwardly with respect to the direction ofrotation when looking towards the corresponding drum member with respectto planes passing through said teeth and lying parallel to the axes ofrotation of the clutch elements.

3. In a car puller the combination of two winding drums, means tojournal both of said drums for rotation, a toothed clutch elementsecured to one end of each drum, a length of cable comprising a cableloop, means to connect one end of said cable loop length to each drum,said clutch element teeth facing in directions for drive of each drum indirection to wind cable on said drum with corresponding unwinding ofcable from the other drum, a common driving element for both of said

